1. Field of the Invention
The present invention relates to a disk drive mechanism for reading data recorded on a disk, such as a compact disk or a laser disk, and, more particularly, to a disk clamping apparatus arranged in a disk drive mechanism, which fixedly sets a disk onto a turntable by the centrifugal force resulting from the rotation of a motor rotating the disk so as to read out data from the disk.
2. Description of the Prior Art
Generally, a disk drive mechanism has a turntable having an upper surface on which a disk is stably set, a motor for rotating the turntable, a clamping device for clamping the disk onto the turntable and a pickup for reading data recorded on the disk.
In the disk drive mechanism, the clamping device includes a rack slidably arranged on a slider member, a cam rotated by the movement of the rack, a clamping arm upwardly and downwardly rotated to be centered with a hinge according to the cam rotation, and a clamp driven according to the upward and downward rotation of the clamping arm for clamping the disk onto the turntable.
The clamping device thus constructed serves to stably set the disk on the turntable to prevent undesirable effects, for example, noise, short-signal and jitter, resulting from the disk being eccentrically set on the table or the disk being vibrated due to an external shock.
FIG. is a front view of a conventional disk drive mechanism, in which a partial cross-section of the mechanism is shown to illustrate the operation of the disk clamping apparatus. In FIG. 1, 1 denotes the disk on which data is recorded or read out, 2 denotes the turntable on which the turntable is stably set, and 3 denotes a motor for rotating the turntable 2.
Further, 4 denotes a rotational shaft transferring the force of the motor 3 to the turntable 2. 5 denotes a pickup for recording or reading data on or from the disk 1. The pickup 5 records or reads data on or from the disk while maintaining a predetermined distance from the disk 1. 6 denotes a slider for moving the pickup 5. The slider 6 has the pickup 5 mounted at one side thereof and a rack 6a is arranged at the other side of the slider 6.
7 denotes a guide bar for guiding the movement of the slider 6, and 8 denotes a cam rotated by the rack 6a engaged with the slider 6. The cam 8 has a gear 8a formed at a portion of its outer periphery, so that the cam 8 is rotatably driven by the rack 6a and gear 8a being engaged together when the rack 6a, disposed on the slider 6, is moved rightwardly and leftwardly. 9 denotes a clamp arm upwardly and downwardly rotated to be centered with a hinge 9a formed at an end of the clamp arm 9 in response to the rotation of the cam 8. 10 denotes a clamp disposed at the other end of the clamp arm 9 for stably fixing the disk 1 onto the turntable 2, and 11 denotes a spring for downwardly biasing the clamp arm 9 to control the pressure applied to the disk 1, set on the turntable 2, from the clamp 10.
With the above-described construction and looking at FIG. 1, when the slider 6 is rightwardly moved along the guide bar 7 by a slider moving means (not shown), the rack 6a arranged on the slider 6 is engaged with the gear 8a formed on the outer periphery of the cam 8. Consequently, the cam 8 is rotated leftwardly (i.e., in the counterclockwise direction).
When the cam 8 is leftwardly rotated, the clamp arm 9 is upwardly rotated and moved centering with the hinge 9a. Upon being rotated, the clamp arm 9 is centered with the hinge 9a, and the clamp 10 is upwardly lifted. Therefore, the disk 1 is removably set on the turntable 2.
When the disk 1 is set on the turntable 2 by an operator, the slider 6 is leftwardly moved along the guide bar 7 by the slider moving means, and then the cam 8 is rightwardly rotated (i.e., in the clockwise direction) according to the movement of the slider 6. By the cam rotation, the clamp arm 9 downwardly descends and centers itself with the hinge 9a by its own weight or by the weight of the clamp 10. Accordingly, the clamp 10 stably fixes the disk set on the turntable 2. Herein, the spring 11 serves to downwardly rotate the clamp arm 9 and to control the pressure of the clamp 10 provided on the disk 1.
Under this condition, when the disk drive mechanism is operated, the motor 3 rotates, so that the rotational force is transferred to the turntable 2 through the rotational shaft 4. As a result, the turntable 2 is rotated and the disk 1 fixed on the turntable 2 by the clamp 10 also is rotated.
Simultaneously with the rotation of the disk 1, the slider 6 is moved leftwardly and the pickup 5 records or reads data onto or from the disk 1.
Hence, the conventional disk clamping apparatus includes the rack being movable on the slider, the cam rotatable according to the movement of the rack, the clamp arm upwardly and downwardly rotatable to be centered with the hinge depending upon the cam rotation, and the clamp for clamping the disk set on the turntable by the upward and downward rotation of the clamp arm. Thus, the structure of this conventional apparatus is extremely complicated.
Accordingly, in such a conventional disk drive mechanism, it is difficult to manufacture the disk clamping apparatus and manufacturing costs are relatively high. Further, the clamp is located on the upper side of the disk 1 and operated upwardly and downwardly. Hence, the disk drive mechanism must be designed so that the entire height of the apparatus, to include the range of motion of the clamp, can be accommodated. Therefore, the mechanism is not compact. Further, the turntable and the clamp for stably supporting the disk are previously limited in structure (e.g., independently designed and manufactured), so that a compact disk and a laser disk, each having a differently sized hole formed at their interiors for stably setting the respective disk on the turntable, are not compatibly used in the mechanism.